1. Field of Invention
The present invention relates to a printing plate mounting system and method therefor. More particularly, the invention relates to a flexographic printing plate mounting system, physical register record plate (PRRP) and method employing the mounting system and PRRP.
2. Related Art
Presently, there exists a number of flexographic printing plate mounting systems. Today, such systems typically employ some method of registering the flexographic printing plate onto a plate cylinder by aligning a pair of microdots formed in the printing plate with respect to a central axis of the plate cylinder. The mounting systems which employ the use of microdots operate on the principal of positioning two microdots which are perpendicular to the making direction of the web.
A trend in the industry has been to use a pair of cameras which are ideally in parallel with a shaft of the mounting plate cylinder. Each camera is operatively connected to a split screen monitor to display the position of the microdots. The microdots, and in turn the printing plate, are manually manipulated to bring the microdots into a center screen, thus registering the plate.
A problem which exists with the use of the microdots is that those alignment techniques currently employed today require a relatively high degree of human intervention to make judgments on alignment and positioning. Frequently, this intervention results in error of the registering of plates. Specifically, each plate may vary slightly in registration from another by virtue of the mounter displacing the microdots slight amounts each time a centering of the microdots is accomplished.
One requirement for high multicolor quality printing to be accomplished is that all of the printing surfaces on the respective color printing plates are properly positioned on their respective plate rollers so that when the web being printed upon is fed into contact with printing plates mounted on the successive plate rollers in the press, the several colors will be applied properly to the web in the desired exact position to form the composite images which together reproduce the original photograph being duplicated. This process is also important in some black and white in some applications.
There remains a need in the art to have a mounting device and method employing the same which is less cumbersome, less expensive and reduces the amount of error which is introduced in registering various plates. In essence, there is a need for a simpler system for mounting flexographic printing plates.